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CVE-2026-70493

Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically

Published: Aug 4, 2026Updated: Aug 5, 2026 Sources: CVE List NVDCWE-1333
6.5MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 77.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

Description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the built-in knowledge search path in backend/open_webui/tools/knowledge_fs.py and backend/open_webui/tools/builtin.py let a chat participant choose a pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file with no time limit, so a crafted pattern such as (x|x)*y and one matching uploaded file line can pin one CPU core and block the event loop. This causes availability impact for every other user of the affected worker. This issue is fixed in 0.11.0.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-1333

Affected Products

open-webui
oss-projectaka open-webui/open-webui
open-webuiOn-premWeb App
AI / ML / ai-agent-tooling

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/open-webui/open-webui/commit/3ab2026262ef6f09810e4d235c5f9a9cb903e595
github.com
https://github.com/open-webui/open-webui/pull/27471
github.com
https://github.com/open-webui/open-webui/releases/tag/v0.11.0
github.com
and 1 more references View all →

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